Three Turkish soldiers were killed and another wounded on Tuesday in southeast Turkey when a mine exploded in the latest attack on security forces blamed on militants from the outlawed Kurdistan Workers' Party (PKK).
Kurdish militants detonated a remote-controlled mine as a military convoy passed by in the Arakoy region of Sirnak province bordering Iraq and Syria, security sources told AFP.
The explosion triggered clashes between Turkish soldiers and PKK rebels, they said, confirming a report by the official Anatolia news agency.
The initial toll stood at two but one of the two injured soldiers died in hospital, bringing the number of dead to three.
The attack was blamed on the PKK, which has stepped up its strikes on the security forces in the last two weeks, as Turkish warplanes bomb its positions in northern Iraq.
The spiral of violence sparked by the killing of 32 pro-Kurdish activists last month in a town on the Syrian border by suspected Islamic State (IS) militants has left a 2013 ceasefire between Ankara and the PKK in tatters.
According to an AFP toll, 20 members of the Turkish security forces have been killed in attacks blamed on the PKK since the current crisis began.
The PKK, blacklisted as a terrorist group by Turkey and its Western allies, took up arms for self-rule in 1984 in an armed struggle which has claimed tens of thousands of lives.
Meanwhile, an explosion hit a natural gas pipeline transporting gas from Azerbaijan to Turkey in the eastern province of Kars, the Anatolia news agency said.
There was no immediate claim but the PKK have repeatedly targeted energy infrastructure in Turkey in the past.
Turkish warplanes have for over a week carried out hundreds of sorties over northern Iraq, with official media claiming that that they have caused significant damage to PKK infrastructure and killed some 260 militants.
Ankara is waging a two-pronged cross-border "anti-terror" bombing campaign against IS militants in Syria and PKK rebels in northern Iraq. But so far the raids have overwhelmingly targeted the Kurdish rebels.
Ten Turkish F-16s strafed PKK targets in northern Iraq, including its Qandil Mountain headquarters, for around three hours.
On Sunday, two Turkish soldiers were killed and 31 wounded in a suicide bombing by a PKK militant in the east of the country, the first time the group has used the tactic in the current escalation.
The PKK confirmed on Monday the attack was carried out by one of its guerrillas with the nom de guerre of Andok Eris.
It said the attack was a reprisal for a Turkish air raid that pro-Kurdish media said killed several civilians on Saturday morning but the army insisted targeted "terrorist" infrastructure.